The statements in this section merely provide background information related to the present disclosure and may not constitute prior art.
Dimensional accuracy of scroll components is an important parameter during manufacturing. Scrolls, to optimally perform in a scroll compressor, should minimize leakage, wear, and fracture. Thus accurate final dimensions are important. Scroll components of scroll compressors are frequently manufactured by a molten metal process (“casting”). In one casting method, molten metal, such as liquid gray cast iron, is poured into a cavity, which then solidifies and forms a scroll after solidification is complete. Molds used in the casting process, into which the molten metal flows, are frequently composed of sand, binder, and/or a ceramic coating and may not have full structural rigidity. When the liquid metal contacts the mold wall surfaces, pressure is exerted on the mold, which potentially can cause mold wall expansion. Gray cast iron is prone to solidification expansion, believed to be due in part to having a high carbon or graphite content. Such a phenomenon can contribute to dimensional variation and tolerance increases.
Furthermore, sometimes, a “skin effect” is observed, which is believed to be attributable to the complicated thermodynamic, kinetic and metallurgical/chemical interactions that take place at the interface between the metal and ceramic casting material during solidification and cooling. Such a skin effect may necessitate removal of the modified surface. To accomplish accurate dimensions after casting, often extensive, complicated and expensive machining is used on the raw castings to convert them into a useable scroll.
It would be desirable to improve dimensional accuracy of scroll components produced during manufacturing and/or to reduce the amount of machining and other attendant processing required during the scroll component manufacturing process to improve manufacturing efficiency and product quality.